Jaundice, as is well known, is a condition one of the characterizations of which is yellowness of the skin of a person and is due to deposition of bile pigment resulting from excess bilirubin, known as hyperbilirubinemia, in the blood.
Bilirubin, in its indirect form, is potentially harmful, for example, to the central nervous system of a newborn infant. The severity of the damage caused is related to the level of bilirubin in the serum of the blood. In its most severe form, this damage is called kernicterus. After jaundice has been detected, treatment regimens, such as exchange transfusions and phototherapy, are commonly used, when considered necessary, to prevent levels of bilirubin known to cause kernicterus. It is currently felt that lower levels of bilirubin may also be one of the causes for minimal brain dysfunction, a condition thought to be responsible for a large majority of learning disorders in children. If such a relationship is true, early detection and treatment of lower level hyperbilirubinemia becomes even more critical.
The practice now commonly utilized in hospital nurseries for detecting jaundice is visual. A positive diagnosis is then normally verified by a serum bilirubin test using established laboratory techniques. While these techniques provide a reasonable indication of an infant's potential for kernicterus in most cases, the techniques now utilized have been shown to be inadequate in at least some instances, such as, for example, in the occasional development of kernicterus in infants with lower bilirubin levels (under 10 mg/100 ml).
The disadvantages of the current visual detection practice and laboratory confirmation process include the danger of missing many lower-level hyperbilirubinemias, causing a delay in the initiation of treatment until the laboratory results are known, causing discomfort to the infant, risking infection to the infant from the blood sample withdrawal process, being relatively expensive, and/or being time consuming and unsuited for mass screening.
Three factors must be normally considered in the visual detection process: experience of the physician or nursing staff, skin pigmentation of the infant, and nature of the environmental lighting of the nursery or hospital environment. Only the experienced nurse or medical practitioner can now consistently indentify the onset of jaundice.
In addition to the initial detection process, proper monitoring of bilirubin level during treatment for jaundice is likewise important. Improper monitoring can result in excessive or insufficient phototherapy or unintended delay in administering an exchange transfusion. Both initial detection of jaundice and the monitoring of jaundice during therapy are therefore critical in the treatment of the disorder.
Thus, the process of detecting jaundice in current nursery practice is based upon one vital sign -- subtle color change of the infant's skin. Obviously, if subjective judgment in recognizing a subtle color change can be replaced by a dependable quantitative apparatus and method to detect jaundice, this would provide a needed improvement.